The purpose of this 52-week study is to evaluate the long-term safety (in terms of adverse events, COPD exacerbations, laboratory, ECG, and Holter findings, vital signs, use of rescue medication and lung function) of GSK573719/GW642444 Inhalation Powder 125/25mcg in subjects with COPD. The long-term safety of GSK573719 Inhalation Powder 125mcg will also be evaluated. A placebo arm is included to evaluate these products compared to an inactive control.